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Published byJeffry Sullivan Modified over 9 years ago
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Chowan River TMDL Development Raccoon/Sappony Area 09/8/04
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Impaired Waters in the Blackwater River Drainage Raccoon Creek – Fecal Coliform Sappony Creek – Fecal Coliform Spring Branch – General Standard (Benthic)
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Fecal Coliform Impairments Impaired Stream Segments in the Nottoway River watershed
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TMDL Development Historical data analysis Source assessment Bacterial source tracking Modeling Allocation
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Water Quality Data Analysis Location of VADEQ water quality monitoring stations used for TMDL assessment in the Nottoway River watershed
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Water Quality Data Analysis Fecal Coliform Concentrations
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Water Quality Data Analysis Location of BST water quality monitoring stations in the Nottoway River watershed
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Water Quality Data Analysis E. coli concentrations
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Water Quality Data Analysis Statistical Analysis of Water Quality Measurements versus Precipitation to determine the relationship between rainfall and water quality Analyzed relationships for seasonal trends No seasonal trends found
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Source Assessment Identification of Sources DEQ/DCR/Locality records Ag Census Habitat Analysis Stakeholders, local knowledge – improve estimates BST Delivery Mechanisms Direct Land-applied Exported Out of Watershed Temporal Variation Migration Patterns/Resident Populations Import/Export of agricultural/STP waste?
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Human (2004) ImpairmentPopulation Housing Units (HU) HU with Sewer HU with Septic HU with Other Raccoon Creek Sappony Creek 773 998 394 448 49 67 311 352 34 29
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Human Sanitary sewer Overflows - reported to DEQ Exfiltration – rate from literature Failing septic systems Rate based on age of house Straight pipes U.S. Census and VDH consultation
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Pets (2004) ImpairmentDogsCats Raccoon Creek210235 Sappony Creek239268
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Livestock - 1997 ImpairmentAll CattleBeefDairyHogHorseSheep Raccoon Creek 22411501,8131814 Sappony Creek 396178401401714
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Wildlife Population ImpairmentDeerTurkeyGooseDuckMuskratRaccoonBeaver Raccoon Creek Sappony Creek 1,272 654 274 177 165 115 421 216 18,947 10,603 3,038 2,480 287 189
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Bacterial Source Tracking Location of BST stations in the Nottoway River watershed
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Modeling Hydrologic model Runoff model HSPF Water Quality model Source Assessment Results HSPF Model Calibration and Validation Based on data availability, period of interest
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Modeling
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VADEQ Station 5ARNC003.36 and USGS Station #02045500
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Modeling VADEQ Station 5ASAP013.69 and USGS Station #02045500
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Hydrologic Calibration
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Modeling Source Loads Source Characterization Fecal production / densities / distribution Delivery Mechanisms Direct Land-applied Exported Out of Watershed Temporal Variation
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Load Characteristics
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Model Load Characterization “Direct to Stream” Loads Point Sources: Design Flow/Fecal Discharge Overflows: Reported overflow volume Characterize Volume and Duration Human: Straight pipes “Land Applied” Loads Wildlife, Livestock, Pets Transported to stream during runoff producing event Use measured waste characteristics Compute die-off in between events Human: Failing septic systems Application timing
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Wildlife
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Livestock Average percentage of collected livestock waste applied throughout year
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Livestock Average time dairy milking cows spend in different areas per day
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Livestock Average time dry cows and replacement heifers spend in different areas per day
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Livestock Average time beef cows not confined in feedlots spend in areas per day
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Allocation Quantify Current Source Conditions Run model with present-day sources Develop reduction scenarios that will meet water quality standards 100% reduction in straight pipes, 25% reduction in failed septic systems 100% reduction in straight pipes, 50% reduction in livestock direct deposition Allocate loads to each source
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Livestock - 2002 ImpairmentAll CattleBeefDairyHogHorseSheep Raccoon Creek 29217201,592413 Sappony Creek 412188393,6905419
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Allocation
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